The present invention relates to a process for the bioconversion of a cellulose containing organic waste material to a highly nutritious fodder or fodder supplement and, more particularly, to a process incorporating an inoculum containing a mixture of aerobic and anaerobic microorganisms utilized for the cleavage of cellulose into simple saccharides and assimilation thereof into proteinacious material and lactic acid, resulting in the conversion of a waste material into a highly nutritious self preserving fodder or fodder supplement.
In today's industrialized world, organic waste materials are produced daily in immense quantities, most of which end up in the sewage system or in landfills. Therefor, the conversion of such waste materials into usable products is of economical and environmental importance.
By far, the most common constituent of agricultural and some industrial waste materials is cellulose. Cellulose is found in planta waste material, in paper waste products and even in herbivorial livestock manure (which, in many cases fail to completely digest cellulosic materials therein) and can consist of as much as 50% of the dry weight of some of these aforementioned waste materials. Various processes known in the art are designed for the conversion of such waste materials into various products, including usable nutritious end products, such as fodder or fodder supplements.
Presently, several distinct processes for conversion of cellulose containing wastes into fodder or fodder supplements exist. These processes typically employ biochemical means, biological means or combination thereof for effecting conversion of the cellulose contained in organic wastes, typically composed of plant material, into a fodder or fodder supplement.
One process which utilizes both biochemical and biological means for the conversion of waste materials into fodder is disclosed in U.S. Pat. No. 4,041,182. This process relates to the conversion of agricultural waste materials, by a fermentation process utilizing edible microbial organisms into proteinaceous animal feed product. Two processes are used successively in this process, such that soluble lower molecular weight intermediates acquired from a first biochemical step are then separated from the waste material and provided for a second biological step to be assimilated into proteins.
Similar processes for the conversion of plant and manure waste materials into fodder are also disclosed by U.S. Pat. Nos. 4,018,650; 3,968,254; and 3,711,392. In these patents, microorganisms, which constitute a protein biomass, are produced by culturing these microorganisms in a medium containing hydrolyzed cellulose and/or other polysaccharides such as starch provided from a biochemical hydrolysis step.
Although the patents above describe a process which can effect a partial conversion of cellulose into protein stored in the form of an edible biomass, both of the processes described above posses significant drawbacks.
The successive use of two separate and distinct chemical and biological processes, necessitates the separation of the soluble lower molecular weight intermediates following the biochemical step, prior to feeding these lower molecular weight intermediates to the biological step, which reduces the efficiency of the process as a whole, because of low intermediate convertibility and/or losses of intermediates incurred by the separation process. The process also becomes complicated, time consuming and therefor cost-ineffective.
Other processes utilizing only biological steps for converting cellulosic waste material to a nutrition product also exist.
One such process is described in U.S. Pat. Nos. 5,198,252 and 5,312,632. These patents teach a process for the manufacture of fodder and/or soil improving agents by anaerobic or aerobic fermentation of environmentally disturbing aquatic plants mixed with agricultural waste material, pectinases and molasses which are added to aid the conversion process.
There are a number of serious disadvantages associated with the process disclosed in the above patents. The first of lies in the fact that the process requires mixing of the comminuted wastes with a ready-to-use commercially available enzyme, namely pectinase, which is a relatively expensive product and has reduced cleaving efficiency compared with the efficiency of an enzyme formed in vivo by a microorganism.
Another significant shortcoming of this process is the introduction of molasses, which act as a source of glucose and pentozes. It is well known in the art that these carbohydrates inhibit the hydrolysis process of cellulose effected by a starter culture and thus reduce the efficiency of the whole process. As a result, the cellulose initially contained in aquatic plants and vegetable wastes may remain unconverted within the fodder.
Furthermore, the above carbohydrates may also, to some degree, inhibit the pectinase, thus preventing the hydrolysis of pectin initially contained in the wastes. Pectin may also remain unconverted in the fodder. All of the above are associated with receiving a food product which has a high content of cellulose and low digestibility.
Finally, although these patents teach a process for degrading cellulose, the resultant end product contains very little nutritious value as it does not contain newly generated proteinacious material but rather a high quantity of newly generated lactic acid which is of limited nutritional value as compared with proteins. In this respect the process is very similar to a conventional molasses lactic acid fermentation process.
There is thus a widely recognized need for, and it would be highly advantageous to have, a process for producing a fodder or other nutrition products from cellulose containing waste materials devoid of the above limitation and which results in higher protein content, as well as higher digestibility.